monitor melodrama

I just moved my computer to another room.When I attached a monitor , the monitor turns on, but nothing happens on the screen at all. I tried 4 separate monitors that I know work, so it's got to be something with the computer. What's causing this?.

What exactly appears on the monitor when 'you said nothing at all'... total blank?
The monitor is plugged into a power source? Monitors and CPU usually have separate power plugs unless you have 'relay' cables that takes power direct from the CPU
Is the CPU (Computer) cooler fan running? Even if your hard disc crashed, you'll likely enter the 'bios' page, unless other hardware damage is involved.
Are the processor lights blinking?